Plastic-Wrapped Bananas Not So Crazy?

The Daily Show ran a very funny bit on Del Monte's new single serving, plastic wrapped bananas the other night. Though they might not be as crazy as they sound...

h/t: Daily Mail:

These bananas, intended to be sold at convenience stores and gas stations, are wrapped in bags containing "Controlled Ripening Technology" (some sort of ethylene inhibitor?) that is said to extend shelf life up to 6 days. The bananas are placed in their bags while green and ripen more slowly than those piled on the shelf. They're being marketed as 'Natural Energy Snack on the Go,' for a U.S. cost of $1 each. 7-Eleven enthusiastically adopted these single serving bananas in thousands of stores last year due to customer disdain for brown bananas and the fewer (carbon/cost-intensive) deliveries that are required to stock produce with an extended shelf life.

It's also been pointed out that getting fresh, (culturally?)-appealing produce into quickie marts and bodegas in inner cities and isolated small towns might do more good alleviating food deserts than it does harm in generating extra trash.

Ergot in the Rye

Stopping at the charity field on the way back from pollinating, I noticed a ripening rye cover crop the next field over - and decided to look for my friend, ergot.*

I couldn't believe my luck! There were little black pods sprouting from rye spikes all over the edge of the field. This is a very exciting creature to a plant pathologist - and one that's had quite an impact on European history...

Orange Mystery Dust

We were only a few pitches into the first inning and everyone's feet were completely orange. No one could figure out why the grass had been spray painted.

Luckily, there was a plant pathologist in center field.

Evolving Pesticide Resistance

It's been estimated that genetic resistance to every pesticide that will ever be invented already exists in some microbe in some field, somewhere in the world (simply because there are so many individuals of each species). If you invent an incredible new spray that kills, say, Phytophthora infestans, you'd know that somewhere in the world there is a little P. infestans mycelium or spore that is already resistant. If you start spraying thousands and thousands of acres with your new pesticide, you may have a season or a few without late blight, but it's only a matter of time before this little guy gets into your field and finds a smorgasbord all for himself.

WOW!

Now, this is what I call huitlacoche!

I've seen lots of cool stuff in our maize research fields, but this is definitely this year's highlight so far! Some of the diversity panel landraces are particularly susceptible to corn smut, but none can hold a candle to our sweet corn varieties. This specimen was wrapped in a husk twice as big as any actual ears.

Organic Crop Rotations

Crop Rotation on Organic Farms: A Planning Manual (Mohler and Johnson, free download here) is the result of an organized effort to capture local knowledge of popularly-nominated expert organic vegetable growers in the Northeast.

It was interesting to listen to the seminar speaker describe the impetus and main findings of this study. Textbook descriptions of crop rotation apparently tend to be rigid and idealistic - so the authors made an attempt to describe them in a more intuitive fashion that will facilitate on-the-fly rotations that allow for unpredictable weather and markets.

Crop rotations are key to preventing the buildup of host-specific pests and pathogens, while evening out soil nutrition when chemical applications aren't an option. Completely stripped down, they basically recommend that you keep a given plant family (e.g. tomatoes-potatoes-peppers-eggplants, legumes or melons-squash-cucumbers) in a given plot for only 1 in every 4 years. Grasses can be cycled more quickly since our local pests and pathogens here tend to be specific at the Genus instead of Family level. They also give common sense advice on how to prioritize which crops should go in the best fields.

I was shocked to hear that these farmers have virtually NO weeds in their fields. Apparently they pull this off with zero-tolerance for weed seed contamination in crop seed or compost and summer fallows (e.g. no bare dirt), finished off with hand pulling. On most farms, weeds are the No. 1 problem - so this is pretty impressive management!

I was also impressed by the extensive use of intercropping.

During the Q&A, we learned that overcomposting is a major problem (that doesn't help keep weeds down and is at times absurdly unsustainable). I guess being surrounded by horse farms looking to get rid of tons of manure is tempting towards overuse...

These farmers don't rotate animals onto their fields since they don't want the soil (that they work so hard to fluff up) to get compacted. They may occasionally bring in chickens or ducks (to eat slugs), but having to deal with fences to keep the animals in and predators out is rarely worth the effort.

One audience member asked if today's expert organic farmers are any better than their counterparts in the Middle Ages. The speaker mused that since all of this knowledge simply arose from lifetimes of local observation, that they probably aren't.

(Outside of new technologies of course!)

Virus Melts Caterpillar!

I recently saw a presentation on the molecular biology of baculoviruses and was blown away by the missed opportunity to discuss their ecology.
If the speaker had introduced this fascinating group of viruses properly, the audience would have been much more interested in what he had to say.

The lifecycle of a typical baculovirus begins when a caterpillar ingests virion particles while feeding on a leaf. The virus exists in two different forms - a tough protective structure that can survive the elements and an infective structure that travels quickly through the insect's body.

The former version of the virus can withstand harsh environmental conditions -heat, solar radiation and rain - but it breaks down in the incredibly alkaline environment of an insect's midgut (pH as high as 10 or 12!). This alkalinity (on par with ammonia!) dissolves the virion's protective matrix and allows the virus' nucleic acids to climb into the insect's gut cells. The virus then transforms to its latter form and spreads throughout the body by budding off each infected cell in little bubbles of cell membrane.

In Manduca sexta (pic.), this virus also seems to induce the caterpillar to wander up high into branches before it dies. This was noticed in Germany in the 1900s, where it was called "wipfelkrankeit," or, tree-top disease. At this point the virus enters its lytic phase, bursting cells and inducing the caterpillar's own cells to produce chitnases that digest the exoskeleton. The sick caterpillar literally melts, leaving only a black, virus-filled stain on the leaf. The slurrified caterpillar drips and falls down through the branches, contaminating every leaf it touches. Our very hungry caterpillar got infected by eating the liquefied corpse of another.

Because these virion particles are water soluble, they can likely be found on every land mass and in every body of water on Earth - and are certainly present on most of the fruits and veggies you eat! Luckily, they're harmless to us. In fact, they're so incredibly species-specific that they haven't been very useful as biopesticides since growers usually need to control more than one bug at a time. There are just a few commercial preparations, including one that the USFS uses to control gypsy moths. Baculovirus biopesticides (like many forms of biocontrol) are kinda tricky to use, and therefore expensive, but a few labs are working on discovering/engineering more effective viruses strains.

"Eating Animals"

I listened to Jonathan Safran Foer discuss his new book, Eating Animals, today on On Point.

What I've heard to date suggested he would be an irrational extremist, but on the radio at least, he was calm, logical and (when it came to the economics and logistics of agriculture) accurate.

He asserted that the treatment of animals in industrial agriculture falls below the ethical standards of all people, that people would be revolted if they actually understand how animals are treated and that the only solution is to become a vegetarian (as low-intensity agriculture isn't productive enough to keep 6 billion people in beef and chicken).

A lot of people seem to be freaking out about his book, but his appearance on the radio was reasoned, consistent and offered one possible answer to my question.

He said that he's never met someone who was a proponent of factory farms, but I think that may just reflect his social circles. I'm all for legislating the humane treatment of animals, but I don't think that's mutually exclusive with high intensity animal ag.

Pretty Plant Diseases

Our local Ellis Hollow blog has some nice poinsettia pics. As I mentioned earlier, a plant disease is responsible for bushy, heavily-flowered (well, they're not really flowers) varieties of poinsettia.

Phytoplasma infections commonly cause symptoms of phyllody (the transformation of flowers into leaf-like structures) and virescence (the production of green flowers). Much like virus-induced tulip color breaks*, phytoplasma infection of poinsettias is commercially valuable.

Modern tulip color breaks (irregular stripes) are actually caused by a genetic mutation (not viral infection), which is much better for long term health of the plant. I don't know if similar genetic improvements have been made to poinsettias.

*The most famous color break tulip, Semper Augustus (pic), marked the peak of the speculative bubble known as tulipomania. In one famous account, a single tulip bulb was supposedly sold for "two lasts of wheat, four lasts of rye, four fat oxen, eight fat swine, twelve fat sheep, two hogsheads of wine, four tuns of beer, two tons of butter, one thousand pounds of cheese, a bed, a suit and a silver cup!"

The Myth of Monocultures

Brendan sent me a link to the new PBS video special based on Pollan's The Botany of Desire. Ironically, I had been eyeballing the same book on my shelf the past few weeks wondering if it was due for a re-read.

The PBS special was very well done and I definitely recommend it.

The last 15 minutes though (an uninformed tirade against modern agriculture), were unwelcome and irritating. One telling moment was a local ag scientist lamenting the "tragic" public rejection of the environmentally-friendly Bt potato, followed by more fear-mongering by a partisan lobbyist.

Pollan should limit his lectures to topics he understands - which wears thin as he waxes on the horrors of monocultures. Plants (including crops) are in a continual arms race with pests and pathogens. The plants keep finding new ways to protect themselves while the parasites "keep trying to pick the lock." Picture a landscape filled with many different kinds of potatoes. According to the classic version of this story, a parasite that stumbles upon a new way to break into a certain potato variety may wipe out all individuals of this variety but it won't kill EVERY potato on the landscape.

The problem with this story is that plants varieties that look very different don't necessarily have different disease and pest resistance genes. Just like humans, which are known for tremendous phenotypic diversity, can be extremely susceptible to the same flu and HIV germs across all ethnicities, all the multicolored potatoes in the above picture may be similarity susceptible to diseases like late blight.

It's not so surprising that crops are notoriously vulnerable to parasites when you meet their wild relatives. The fruits and grain of the undomesticated relatives are usually barely edible - tiny, fibrous and full of poisons. It should be no surprise that the same qualities that humans love in their food (lots of easily-digested calories) are appreciated by many other creatures as well. Plant breeders have countered this inherent susceptibility by introgressing (moving) key resistance genes from wild relatives of crops into the crops themselves. This process has actually made modern industrial tomatoes more genetically diverse than either traditional Latin American or U.S./European heirloom varieties (although the traditional and heirloom varieties look more diverse).

Theoretically, it would be useful to maintain crop populations with diverse resistance genes. The industrial application of this (multilines) invovles breeding many different versions of a favorite crop variety that are identical except for their resistance genes. As appealing as this idea is, it hasn't really worked out in the real world. The alternate approach (pyramiding) seems to be more effective. Here, many different resistance genes are combined into a single crop variety. Pests and pathogens may be able to overcome a single gene at a time, but it's usually almost impossible to simultaneously overcome several.

PBS' The Botany of Desire also makes a lot of Bt resistance developing in insects exposed to genetically-engineered Bt crops, but this is nothing new. Insects and pathogens develop resistance to all kinds of pesticides - whether they're natural plant chemicals, artificial sprays, or genetically-engineered genes.

Evolution is a fact of life. The pests and pathogens will continue to adapt, and they will eat up our crops if we don't keep ahead of them. It's a problem you can never completely solve - which is good for me and my scientist colleagues!

CNY Agritourism

Some friends came up from Brooklyn to visit me this weekend. We had a very-Upstate Saturday of apple picking and cider, and went to an alpaca farm festival on Sunday.



I picked a well-mixed quarter bushel of red and yellow, sweet and tart apples to make pies with. I'll let you know how it goes.


At first, I thought this machine might be a tree-shaking harvester, but it was a hydraulic cherry-picker with pole-mounted chainsaw and lopper for pruning. The extension to the upper right is a counter-balance for the platform that's lowered in the background.





The ground was littered with ripe and overripe apples, most of which showed symptoms of apple scab, the most economically devastating apple disease in Europe, Asia and the Americas. It's one of those classic diseases that causes largely aesthetic damage, but requires huge amounts of pesticide to maintain consumer acceptability. The low spray, IPM approach used in this orchard makes a lot of sense for a pick-yourself orchard, and the huge amount of uneaten fruit is a testament to the amazing yields capable in well-managed orchards. My friend pointed out scat that appeared to belong to (very happy) deer and bears.


Even at the end of September there were lots of wildflowers in the orchard, particularly yellow goldenrod and purple asters. I noticed that some of the goldenrod plants had highly-compressed shoot tips (see picture). These plants were most likely infected by phytoplasmas. Phytoplasmas are tiny, amorphous bacteria that lack cell walls and are known for two main symptoms: phyllody (the transformation of flowers into leaf-like structures) and virescence (the production of green flowers).


Commercial pointsettias are commonly infected with phytoplasmas intentionally in order to create more bushy, showy plants.

The Life of Norman Borlaug

I just read that Nobel laureate, Norman Borlaug has passed away. He was the architect of the Green Revolution and, without a doubt, has done more good for humanity than any single person who has ever lived.

Monsanto's blog has a nice remembrance of him.

I Heart Smut Fungi

I was excited to find a fair amount of corn smut (Ustilago maydis) in our corn field today. It's one of my favorite fungi.

This fungal parasite has a complex lifecycle that culminates in the infection of a corn plant and the transformation of that plant (usually the kernels) into tumor-like mushrooms. When ripe, these rubbery gray growths rupture, releasing greasy, black spores.


But BEFORE this fungus produce spores, this "maize mushroom" exists as a yummy Mexican delicacy, known as "huitlacoche." It can be cooked up like any other mushroom. Sometimes you can find the canned version in specialty grocery stores, but I doubt it's as good as it is fresh.

Unfortunately, all the smut I found today had already gone to spores...


Another smut disease caused some pretty dramatic agricultural disasters at the turn of the century (before last). A series of devastating wheat smut outbreaks caused hundreds of combine fires as the vehicles stirred up massive clouds of oily smut spores, which were ignited by the movement of the machinery.


A third pretty incredible smut fungus is Microbotryum violaceum. This "anther smut" fungus parasitizes various flowers in the Caryophyllaceae (especially the campions, Silene spp.).

This fungus colonizes and spreads systemically throughout its host plant, permanently sterilizing it. It does this by forcing the plant's female flowers to grow male anthers (which usually contain pollen) and then REPLACING the pollen with its own spores (see picture) - which are then spread by pollinating insects to uninfected plants!

THIS is why Organic Ag is Bad for the Environment

On my way to work this morning I heard a brief story on NPR about the impact of the current late blight epidemic on local farmers.

One organic farmer explained how he would suffer a total loss this year without spraying some sort of fungicide on his crops. Unfortunately, to keep his organic certification, his best option was to spray copper, a naturally occurring chemical
(inset: copper strip-mine in NM).

He said he would usually only have to spray copper on his land in October but because of the intensity of the current epidemic, he has been spraying it every five days.

Picture what impact it has on his local ecosystem to have that amount of heavy metal pollution introduced to it. It would be more sustainable to use a modern synthetic fungicide that has very limited non-target toxicity and rapidly decomposes when exposed to sun and water.

Copper is a "biocide," meaning it hurts all organisms, and it lasts forever...

Outbreak of Irish Potato Famine pathogen

It was recently discovered that infected tomato plants were sold in big box store garden centers throughout the Northeast. The plants are infected with the causal agent of late blight, Phytophthora infestans, a fungus-like brown alga that's closely related to diatoms and kelp. Tomatoes, potatoes and their relatives are extremely susceptible to this pathogen, which was responsible for the Irish Potato Famine. I saw this pathogen decimate potato fields when I interned at a fungicide company after college. The plants just melted into rotting, black piles.

If you have infected plants in your garden you should destroy them and consider safely applying a commercial fungicide. (Don't ever compost sick plants (or weeds), since their spores will often survive or multiple). The guys at our experimental farm have already started spraying our fields, which is a real shame. They usually don't have to spray until late in the summer, but we risk losing a year's worth of data without it. Our cool, wet, cloudy summers in Central New York are perfect for this disease.

Deck Gardening

Someday I'll have a plot of land big enough for fruit trees and maize. In the meantime, I'm making do with my second story, western exposure deck.

This season I have two heirloom tomatoes (Hank and Black Plum), a sunberry, a ground cherry, green beans, snap peas, carrots and a salad mix. I'm also making an attempt to compost in the three black pots (an admitted long-shot). The minimum recommended size for compost piles is generally 3' x 3' x 3' but I'm gonna take a shot anyway. Maybe if I partially cover the tub in plastic it'll retain some heat during the winter...

I direct seeded the cold-weather species (carrots, peas, salad mix) at the beginning of June, following local recommendations. I started the warm weather fruits and beans in the greenhouse and transplanted them a few weeks later.

Shortly afterward I noticed that many of them were beginning to look pretty yellow/pale. Nitrogen deficiency was the first disorder to come to mind. Iron deficiency was also possible, but less likely since my plants did not retain green veins. Since plants are able to relocate some nutrients/micronutrients within their bodies (but not others), it can be an important clue if only the new leaves show symptoms, or only the old leaves. Overall, nitrogen deficiency is a common disorder and produces symptoms consistent with those observed.

Despite this, I was slow to believe nitrogen deficiency was the culprit since I had JUST planted the seedlings in new soil and because both legume species (pea and bean) are able to obtain nitrogen from the air through symbiotic rhizobia bacteria, which live in their roots. We had received a tremendous amount of rain the previous week, so it was also possible that the roots were not functioning well due to flood-induced oxygen deficiency. To test these hypothesis, I poked lots of holes in the soil in 2 containers to aerate them, and shredded clover roots (another legume growing in our lawn) into 2 other containers to inoculate them with the local microbes.

Unfortunately, the plants began to turn white over the next two days so I had to end my experiment and take more drastic action - by buying cheater-fertilizer. With plenty of nitrogen, the garden greened right up.